Generally speaking, printing systems (e.g., printers, copiers, fax machines, etc.) include a print head or print engine for applying visual images (e.g., graphics, text, etc.) on a page, label, or other type of printable media.
A thermal printer, for example, generates pressure and heat which is delivered via a thermal print head assembly to produce an image on print media. In this regard, varying the amount of pressure and/or heat delivered by the thermal print head (e.g., via adjustment mechanisms) results in a range of darker or lighter print being applied onto the media.
A sub-aspect relating to the amount of print head pressure applied during printing relates to pressure differences that may be applied by the print head across the width of the print media (i.e., pressure bias). For example, if the print head pressure applied is greater on one side of the print medium in comparison with the other side of the print medium, the side with heavier pressure applied will have darker print in comparison to the other side which will have lighter print.
With regard to the amount of pressure or pressure bias that is delivered to the print medium via the thermal print head, proper adjustment is needed in order to balance print quality (e.g., accurate black levels) with print head longevity.
In view of the foregoing, a foundational requirement for obtaining optimal outcomes in a printing process is a stable loading mechanism for the print head. In some instances, however, print head loading mechanisms have employed a cantilever structure having a retention/compression spring assembly located at a far side of the loading mechanism for removably retaining the print head on a printer. These types of loading mechanisms, however, can produce a twisting effect due to the cantilever design causing inconsistent pressure loading. This inconsistency may be particularly evident when this design is used across a range of different printers (e.g., varying between individual printers).
Another important aspect relating to print head loading mechanisms is ease-of-use or usability (e.g., a device's effectiveness, efficiency, user-satisfaction, etc.). If a device, such as a printer's print head loading mechanism, is not designed to achieve high usability in its environment then errors and/or delays can occur.
For example, certain printers employ print head loading mechanisms that require tools in order for a user to replace a print head that has reached the end of its useful lifespan (e.g., the print head has been damaged, prematurely failed, deteriorated, etc.). Requiring additional tools to replace a print head decreases a printer's usability given that a user must not only learn to how to perform the process with the tools, the user must consistently store the tools in an accessible location and locate the tools whenever the task needs to be performed.
Therefore, a need exists for more effective systems, devices, and methods for removably retaining a print head assembly on a printer, including but not limited to stable, user-friendly print head loading mechanisms that do not require additional tools in order for a user to replace the print head assembly.